The sacral plexus is a network of nerves located in the lower back, specifically in the region of the sacrum. It is formed by the anterior rami of the L4 to S4 spinal nerves. This plexus plays a crucial role in transmitting nerve signals to the lower limbs and pelvic region, controlling movement and sensation. Key nerves that arise from the sacral plexus include the sciatic nerve, which is the largest nerve in the body, and the pudendal nerve, which innervates the pelvic floor. Dysfunction in the sacral plexus can lead to pain or weakness in the legs and pelvic area.